content: /*
   * Copyright 2016-present David Karnok
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package hu.akarnokd.rxjava3.basetypes;
  
  import org.reactivestreams.*;
  
  import io.reactivex.rxjava3.exceptions.*;
  import io.reactivex.rxjava3.functions.Function;
  import io.reactivex.rxjava3.internal.subscriptions.SubscriptionHelper;
  
  /**
   * If the main source fails, resume with another Nono returned from
   * a function receiving the error.
   */
  final class NonoOnErrorResume extends Nono {
  
      final Nono source;
  
      final Function<? super Throwable, ? extends Nono> errorHandler;
  
      NonoOnErrorResume(Nono source, Function<? super Throwable, ? extends Nono> errorHandler) {
          this.source = source;
          this.errorHandler = errorHandler;
      }
  
      @Override
      protected void subscribeActual(Subscriber<? super Void> s) {
          source.subscribe(new OnErrorResumeSubscriber(s, errorHandler));
      }
  
      static final class OnErrorResumeSubscriber extends BasicRefQueueSubscription<Void, Subscription>
      implements Subscriber<Void> {
  
          private static final long serialVersionUID = 5344018235737739066L;
  
          final Subscriber<? super Void> downstream;
  
          final Function<? super Throwable, ? extends Nono> errorHandler;
  
          boolean once;
  
          OnErrorResumeSubscriber(Subscriber<? super Void> downstream,
                  Function<? super Throwable, ? extends Nono> errorHandler) {
              this.downstream = downstream;
              this.errorHandler = errorHandler;
          }
  
          @Override
          public void cancel() {
              SubscriptionHelper.cancel(this);
          }
  
          @Override
          public void onSubscribe(Subscription s) {
              SubscriptionHelper.replace(this, s);
              if (!once) {
                  downstream.onSubscribe(this);
              }
          }
  
          @Override
          public void onNext(Void t) {
              // never called
          }
  
          @Override
          public void onError(Throwable t) {
              if (!once) {
                  once = true;
                  Nono np;
  
                  try {
                      np = errorHandler.apply(t);
                  } catch (Throwable ex) {
                      Exceptions.throwIfFatal(ex);
                      downstream.onError(new CompositeException(t, ex));
                      return;
                  }
  
                  np.subscribe(this);
              } else {
                  downstream.onError(t);
              }
          }
  
          @Override
          public void onComplete() {
              downstream.onComplete();
          }
      }
  }
  